[Mlir-commits] [mlir] [mlir][EmitC] Expand the MemRefToEmitC pass - Lowering `CopyOp` (PR #151206)

[Paul Kirth]

================
@@ -159,6 +185,66 @@ struct ConvertAlloc final : public OpConversionPattern<memref::AllocOp> {
   }
 };
 
+struct ConvertCopy final : public OpConversionPattern<memref::CopyOp> {
+  using OpConversionPattern::OpConversionPattern;
+
+  LogicalResult
+  matchAndRewrite(memref::CopyOp copyOp, OpAdaptor operands,
+                  ConversionPatternRewriter &rewriter) const override {
+    Location loc = copyOp.getLoc();
+    MemRefType srcMemrefType = cast<MemRefType>(copyOp.getSource().getType());
+    MemRefType targetMemrefType =
+        cast<MemRefType>(copyOp.getTarget().getType());
+
+    if (!isMemRefTypeLegalForEmitC(srcMemrefType))
+      return rewriter.notifyMatchFailure(
+          loc, "incompatible source memref type for EmitC conversion");
+
+    if (!isMemRefTypeLegalForEmitC(targetMemrefType))
+      return rewriter.notifyMatchFailure(
+          loc, "incompatible target memref type for EmitC conversion");
+
+    emitc::ConstantOp zeroIndex = rewriter.create<emitc::ConstantOp>(
+        loc, rewriter.getIndexType(), rewriter.getIndexAttr(0));
+
+    auto createPointerFromEmitcArray =
+        [loc, &rewriter, &zeroIndex](
+            mlir::TypedValue<emitc::ArrayType> arrayValue) -> emitc::ApplyOp {
+      int64_t rank = arrayValue.getType().getRank();
+      llvm::SmallVector<mlir::Value> indices;
+      for (int i = 0; i < rank; ++i) {
+        indices.push_back(zeroIndex);
+      }
----------------
ilovepi wrote:

You can use the `SmallVector (size_t Size, const T &Value)` constructor to avoid the loop and subsequent `push_back()`s. If nothing else,  its a good practice to `reserve(rank)` elements before the loop starts, and avoid potential allocations.

https://github.com/llvm/llvm-project/pull/151206